General data and statistical analysis
Sixty patients with giant lumbar disc herniation underwent more than 1 year of conservative treatment and continuous follow-up. All patients had at least one MRI review within 1 year of treatment, and the results of the first and final MRI examinations were compared. Thirty-six men and 24 women ranging in age from 19 to 58 years (36.37 ± 9.56 years) were enrolled in the study. The protrusion rate before treatment was 82.16% ± 14.58%, the protrusion rate after treatment was 32.20% ± 30.80%, and the protrusion absorption rate was 59.48% ± 38.62%. The Japanese Orthopedic Association (JOA) score before treatment was 11.15 ± 3.06, the JOA score 3 months after treatment was 18.70 ± 3.78, and the JOA score 1 year after treatment was 23.47 ± 4.14.
All 60 patients were divided into the positive bull’s eye sign group (n = 30) and the negative bull’s eye sign group (n = 30). There were no statistically significant differences in the patients’ general pretreatment data, including sex, age, and protrusion rate, between the two groups (P > 0.05). After treatment, the protrusion rate in the positive and negative bull’s eye sign groups was 14.41% ± 14.37% and 49.99% ± 32.70%, respectively (P < 0.05). The absorptivity in the positive and negative bull’s eye sign groups was 83.09% ± 15.54% and 35.87% ± 40.49%, respectively (P < 0.05) (Table 1).
Table 1. Comparison of sex, age, protrusion rate, and absorption rate
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Cases
|
Years
|
Protrusion percentage before treatment (%)
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Protrusion percentage after treatment (%)
|
Absorptivity (%)
|
Men
|
Women
|
Bull’s eye sign(+)
|
17
|
13
|
37.80 ± 8.65
|
83.74 ± 13.68
|
14.41 ± 14.37
|
83.09 ± 15.54
|
Bull’s eye sign(-)
|
19
|
11
|
34.93 ± 10.34
|
80.59 ± 15.50
|
49.99 ± 32.70
|
35.87 ± 40.49
|
test value
|
c2 = 0.278
|
t = 1.165
|
t = 0.834
|
t = -5.455
|
t = 5.963
|
P value
|
0.598
|
0.29
|
0.408
|
0.000
|
0.000
|
The JOA scores were compared between the patients in the positive and negative bull’s eye sign groups before treatment, 3 months after treatment, and 1 year after treatment. There was no statistically significant difference in the JOA scores of patients in the two groups after treatment (t = −1.057, P > 0.05). However, there were statistically significant differences in the JOA scores between the two groups 3 months after treatment (t = 4.368) and 1 year after treatment (t = 6.234) (P < 0.05) (Table 2).
Table 2. Comparison of JOA scores before treatment and 3 months and 1 year after treatment
|
JOA score
|
Before treatment
|
Three months after treatment
|
One year after treatment
|
Bull’s eye sign(+)
|
10.73 ± 3.14
|
20.57 ± 2.99
|
26.07 ± 1.82
|
Bull’s eye sign(-)
|
11.57 ± 2.97
|
16.83 ± 3.60
|
20.87 ± 4.19
|
test value
|
t = -1.057
|
t = 4.368
|
t = 6.234
|
P value
|
0.295
|
0.000
|
0.000
|
The JOA scores before treatment were compared with the scores at 3 months after treatment and 1 year after treatment. In the positive bull’s eye sign group, a significant difference was found between the pretreatment and 3-month post-treatment scores (t = 12.421, P < 0.05) and between the pretreatment and 1-year post-treatment scores (t = 23.148, P < 0.05). Likewise, in the negative bull’s eye sign group, a significant difference was found between the pretreatment and 3-month post-treatment scores (t = 6.182, P < 0.05) and between the pretreatment and 1-year post-treatment scores (t = 9.919, P < 0.05) (Table 3).
Table 3. Comparison of JOA scores 3 months and 1 year after treatment versus before treatment
|
Time of therapy
|
JOA score
|
Test value
|
P value
|
Bull’s eye sign(+)
|
Three months after treatment
|
20.57 ± 2.99
|
t = 12.421
|
0.000
|
Before treatment
|
10.73 ± 3.14
|
One year after treatment
|
26.07 ± 1.82
|
t = 23.148
|
0.000
|
Before treatment
|
10.73 ± 3.14
|
Bull’s eye sign(-)
|
Three months after treatment
|
16.83 ± 3.60
|
t = 6.182
|
0.000
|
Before treatment
|
11.57 ± 2.97
|
One year after treatment
|
20.87 ± 4.19
|
t = 9.919
|
0.000
|
Before treatment
|
11.57 ± 2.97
|
Case description
A representative case of a patient who underwent dynamic follow-up with enhanced MRI is herein presented. A 38-year-old woman with a 1-year history of lumbago with right lower limb pain developed exacerbation of her symptoms for 1 week in January 2018. The patient visited our hospital. She had no symptoms of cauda equina compression, and the hospital recommended surgical treatment; however, the patient refused surgery.
A physical examination showed right paraspinal tenderness (+) of L5/S1 that radiated to the right lower extremity. In the straight leg raise test, the result on the left side was 70° (−) and that on the right side was 60° (+). The muscle strength in both lower extremities was normal, and tactile sensation in the lateral right lower extremity was decreased compared with the contralateral side. The JOA score was 19. Contrast-enhanced MRI showed no obvious high signal around the protrusion, and the bull’s eye sign was absent (Figure 4, A1–A5). After 4 months, reexamination showed no remission in clinical symptoms, imaging showed increased protrusion, the JOA score was 19, the patient still refused surgical treatment, enhanced MRI showed no enhancement around the protrusion, and the bull’s eye sign was negative (Figure 4, B1–B). After 9 months, the protrusion was not reabsorbed and the pain was improved. The JOA score was 20, enhanced MRI showed no ring enhancement around the protrusion, and the bull’s eye sign was negative (Figure 4, C). After 16 months, the lumbago and leg pain had improved, the radiation pain in the right lower extremity was alleviated, the numbness in the right lower extremity had disappeared, the straight leg test result had increased to 80° on the left (−) and 70° on the right (+), the JOA score was 23, MRI showed partial protrusion resorption, enhanced MRI showed a high-signal shadow around the protrusion, and a positive bull’s eye sign was observed (Figure 4, D). After 21 months, the lumbago and leg pain had disappeared completely, the straight leg had increased to 80° on the left (−) and 80° on the right (−), the JOA score was 27, enhanced MRI showed resorption of the L5/S1 giant disc herniation, and the bull’s eye sign had disappeared (Figure 4, E).